Narrated Ibn 'Umar (RA):

Allah's Messenger (ﷺ) said: "Pray (funeral prayers) over him who said (believed): 'Nothing deserves to be worshiped except Allah'; and pray behind him who says: 'Nothing deserves to be worshiped except Allah'." [ad-Daraqutni reported it through a weak chain of narrators].

وَعَنْ اِبْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ صَلُّوا عَلَى مَنْ قَالَ: لَا إِلَهَ إِلَّا اَللَّهُ, وَصَلُّوا خَلْفَ مَنْ قَالَ: لَا إِلَهَ إِلَّا اَللَّهُ } رَوَاهُ اَلدَّارَقُطْنِيُّ بِإِسْنَادٍ ضَعِيفٍ .‏ [1]‏ .‏